CR123A battery, and how it differs from an 18650
A CR123A (often just "123") is a 3 V lithium battery up to 17 mm across and 34.5 mm long, rated about 1500 mAh. It's used in cameras, flashlights and smart home devices.[1 · Oct 29, 2026][2 · Oct 29, 2026]
| Chemistry | Lithium / manganese dioxide (Li/MnO2), not rechargeable[1 · Oct 29, 2026] |
|---|---|
| Voltage | 3.0 V[1 · Oct 29, 2026] |
| Size | 16 to 17 mm diameter × 33.5 to 34.5 mm long[1 · Oct 29, 2026] |
| Capacity and weight | 1500 mAh; 16.5 g[1 · Oct 29, 2026] |
| Temperature range | −40°C to 60°C[1 · Oct 29, 2026] |
| Standard names | ANSI 5018LC; IEC CR17345[1 · Oct 29, 2026] |
| Also sold as | CR123, CR123A, EL123, RL123A, K123LA[2 · Oct 29, 2026][3 · Oct 29, 2026] |
| Storage | Up to 10 years[2 · Oct 29, 2026] |
CR123A vs 18650
| CR123A | 18650 | |
|---|---|---|
| Size | About 17 × 34.5 mm[1 · Oct 29, 2026] | 18 mm × 65 mm[4 · Oct 29, 2026] |
| Voltage | 3.0 V[1 · Oct 29, 2026] | 3.6 or 3.7 V nominal, depending on chemistry[5 · Oct 29, 2026] |
| Rechargeable? | No[1 · Oct 29, 2026] | Yes, lithium-ion[4 · Oct 29, 2026] |
| Typical uses | Photo, laser sights, security cameras, connected home devices, flashlights[3 · Oct 29, 2026] | Power tools, medical devices, laptops, e-bikes[4 · Oct 29, 2026] |
An 18650 is almost twice as long as a CR123A, so they aren't interchangeable. Some flashlights accept either one battery or the other. Follow the device maker's manual.
What about rechargeable "123" batteries?
Rechargeable lithium-ion cells are sold in a similar size for some devices. Whether a given device is safe with one, given that the voltage is higher than 3.0 V, is up to the device maker. Unverified. We couldn't confirm a reliable source for this yet. Energizer's guide says not to recharge non-rechargeable batteries and to use the type the device maker specifies.[3 · Oct 29, 2026]
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Sources: 1. Energizer 123 lithium datasheet (PDF). 2. Energizer, 123 lithium battery product page. 3. Energizer, Battery cross reference guide (PDF, 2021). 4. Battery University (Cadex), BU-301a: Types of battery cells. 5. Battery University (Cadex), BU-205: Types of lithium-ion. Checked Oct 29, 2026. Inch conversions are our own arithmetic from the millimeter figures. Brand names and trademarks belong to their owners; specs are restated in our own words and tables, not reproduced.